Hot top for ingot molds



' May 5, 1931. w. M. CHARMAN ET A1. i 1,804,204

HOT TOP FOR INGOT HOLDS Filed Dec. 31, 1928 Haar? c7", Har/gioia By WW@6 ATTORNEYS Patented vMay 5, 193i Lamai unirse .STATES PATENT oFFicEWALTER 'M. CHARMAN AND 'HARRY J'. DARLINGTON, 0F YOUNGSTOWN, OHIO; SAIDDARLINGTON ASSIGNOR TO SAID CHARM-AIN' Application led December 31d;1928. Serial No. 329,486.

Our invention relates to that class of devices known as hot tops andwhich are utilized in the casting of steel-ingots and the like, the

function of the hot top being, in general, to-

keep the upper end of the casting molten a suilicient length of time.

lt has been the'custom to make hot tops of clay or other more or lessplastic' material by molding and baking them preparatory to their beingplaced on the ingot mold and after the ingot is poured to strip the hottop olf by a pair of tongs or like implement, but as the material ofwhich the top is formed generally cracks under the heat to which it is'sub'ected, the top tears apart along these cracks uring the stripping;in consequence only that part above the cracks is removed by the tongsand ,it therefore becomes necessary to remove the remaining portion byknocking it olf with a crowbar or the like. This operation is a veryundesirable one because of the intense heat adjacent the ingots, while,furthermore, it is extremely dithcult to thereby remove all of the topmaterial so that a certain amount of the latter is carried with theingot to the soaking pit. Due to the heat in the soaking pit theresidual portion of the hot top frequently melts and runs down thesidesof the ingot to the pit floor so that the latter through gradualaccumulation of the melted hot top material yincreases in thickness andcorrespondingly diminishes the depth of the pit. Additionally theaccumulated hot top material in the pit in connection with otherimpurities also therein accumulated forms a slag which acts as aninsulator around the bottom of the ingot thereby preventing the lowerend of theingot V from being heated to the same temperature as Vthe restof the ingotl which results in the formation of minute cracks near thebottom ofthe ingot which appear when the latter is subsequently rolled.f f

A principal object of our invention, therefore, is the provision of Aanimproved form of hot top through the use of which the disi advantages towhich we have referred are entirely overcome and which in additionpresents numerous advantages over the forms of hot tops heretoforeemployed.

A further object of the invention is to 'provide a hot top which can beused satisfactorily for a plurality of casts; to provide a hot top whichmay be stripped from the mold conditions may be obtained and which maybe so constructed as to bring about the greatestV possible amount ofvpipe elimination in the ingot with a minimum amount of casting metal inthe top and to provide a top of such character that it will freelyfollow and sink with the fluid metal as the latter shrinks during thecooling of the ingot thus resulting in free contraction of the latterand preventing any hanging up of the ingots which frequ-ently'occurswith the. hot tops at present in use and results in cracks inthe ingots.

Still further objects ofthe invention are to reduce the cost of the hottops per ingot; to effect a saving instorage space required for the hottops and the bricks entering into their construction; and to appreciablyreduce the cost of repairs to the soaking pits required because of theaccumulation therein of residual material from the forms of hot topsheretofore generally employed.

Our invention further includes other ob- -use'of which maximum eiciencyin pouring after more particularly `pointed out or which will beapparent to those skilled in the art from the following description ofcertain forms of hot tops embodying the principals thereof andillustrated in the accompanying drawings. Y

In the said drawings Fig. 1 is a top plan View of a hot top constructedin accordance awith'one form of our invention and disposed on the upperend of aningot mold preparatory to the pouring ofthe ingot; Fig; 2 is avertical section of the hot top and .moldl on lineQ-Q in Fig. 1` lookingin the direction of the'arrows and F ig. 3 is a perspective view, of thehot top shown in the preceding figures. Figs. 4, 5 and 6 arerespectively fragmentary vertical sections showing slightly modifiedforms of the invention. The same characters of reference are used todesignate the same parts in several figures.

Referring now more particularly to that form of the invention shown inFigs. 1 to 3 inclusive, the same comprises a hollow casing generallydesignated as 1 which is built up of four separate sections 2, 3, 4, 5,respectively provided at their corners with outwardly directed lugs 6and 7 for the reception of bolts 8 by which the sections are securedtogether to thereby form a single operatively unitary struct-ure. Whilewe frequently prefer to use a built-,up casing of the'general nature' ofthat to which we have referred, the casing may, if desired, be cast as asingle integral unit, while in any case the size and shape of the lowerpart of the casing is such that when entered into the mouth of the moldM with which it is intended to be used, a small clearance C will beafforded ,between the mold wall and the casing extending entirely aroundthe latter. y

The casinor may be provided with one or more sets of oppositely disposedtrunnions for the attachment of lifting hooks when stripping the hot topfrom the mold or moving it about and as a matter of convenience weprefer to provide two sets of these trunnions and \to locate one set 10,10 near the center of gravity of the hot top and the other set 11, 11more nearly adjacent the upper end thereof; under these conditions thelatter set of trunnions may be desirably used when stripping the hot topfrom the mold and the other set when it is desired to turn the hot topupsidedown for .inspection or repairs.

As shown, the casing tapers slightly inwardly from its lower edge and isprovided with an upper interior lining, generally designated as 15, ofrefractory or other suitable material desirably in the form of aplurality of interitting bricks 15. The bricks forming this lining arevertically supported upon an inwardly directed ledge or shelf 16extendina around the casing a short distance above its bottom andintegral with or4 attached to the casing wall and are desirably soarranged that a small clearance space 17 is left between their outerfaces and the casing so as to permit expansion of the bricks whenheated, for in the absence of this clearance, some-of the liningmaterial beingunable to expand under the extreme heat to which it issubjected'may crack orcrumble and thus become unfit for further useafter one or more pourings; however, it is possible to omit theclearance if considered necessary or desirable by constructing the upperlining of refractory or insulating-material having substantiallynegligible expansion or con'- traction such as, for example, so-calledsaw- We have shown the inner faces of the bricks 15 forming the uppercourse of brickwork constituting the mam lining of the casing asslightly inwardly inclined from bottom to top in correspondence with theinclination of the casing wall, this construction giving good results inpractice, but if desired the bricks may be of other shapes with a viewto inducing the greatest possible amount of pipe elimination in theingot with minimum amount of steel in the to'p. Thus, for example, asthe ingot pipe is of generally cone shape, the bricks in the uppercourse might be made in such form that the interior of the hot top wouldbe of generally corresponding shape with a View, as stated, to securing'the maximum amount of pipe elimination.

It will be understood that the upper course of bricks 15 form a more orless permanent part of the hotl top, as a whole, and are thus utilizedfor a'plurality of casts, being removed fromthe mold with the casingafter the completion of each cast. f A lower course of refractory orother suitable material, generally designated as 20, and preferablyformed of bricks 20 is also provided to form a lining for the lower partof the casing adjacent and below the shoulder 16. As in the case of theupper course, these bricks 20 are preferably interfitting and may l beof` any form suitable forthe particular contour of the mold with whichthe hot top is to be used. Desirably this course of bricks entirely,overlies the surface of the casing beneath the ledge 16 as well as thelower edge or face of the casing as best shown in Fig. 2 so that thelower faces of the bricks can rest on the surface of the ingot duringthe'casting operation as hereinafter explained. The bricks or otherrefractory or suitable materialforming the lower course are initiallysecured to and supported from the casing by means of` suitablefastenings, such for instance as pins 21 of wood-or other fusible,

frangible or burnable material extending through the bricks'and intoholes 22 drilled through the lower portion or skirt of the casing, alsoas best shown in Fig. 2.

The casing is also provided with means for eEecting its support on themold pre- A paratory to and during the pouring of the metal, said meanspreferably comprising ears 23 integral with the lugs 6 and 7, extendingoutwardly therefrom and adapted to rest on blocks of wood 24 or othersuitable supports disposed on the upper end of the mold and operative tosupport the hot top with the lower course of bricks andthe skirt of theca'sing extending into the mold for a suitable distance as shown in Fig.2.

Preparatory to the pouring of the metal,l the .hot top is supportedabove the mold byv means of the blocks 24 or other suitable means asshown in Fig. 2 so that the lower v the mold through the hot top untilit rises undesirable as it tends to cause cracks in therein sufiicientlyto enter the clearance space C in which it 'rapidly congeals` or freezesto form a seal at this point. The

teeming of the metal is now continued at a slower rate until the levelthereof is brought to a suitable point in the top, usually from one tosix inches below its upper end depending upon the thermal and physicalcondition of the steel being poured and thewooden blocks 24 or othersupport are then knocked away so as vto allow the hot top to sink withthe metal as i its shrinks in the mold thus insuring a freely floatinghot top. Thus with 'our improved hot top there is no tendency vwhateverfor the ingot to be hung up, that is, to be to any extent suspended fromthe top as frequently occurs with the hot topsfhitherto in use and whichare firmly supported on the upper end of the mold. This hanging up orsticking of the ingot to the hot top is most the ingot but in ourimproved hot top, as soon as the blocks 24 or other supports'areremoved, is entirely supported on the ingot itself and thus free tofollow the latter down as it shrinks in cooling, the undesirablecondition to which we havereferred is entirely prevented.

When the ingot has cooled suiiiciently to permitremoval of the hot top apair of ifting hooks are engaged beneath the trunnions ll 'and thecasing and upper course of bricks liftedoff the mold as a unit, whilethe lower course of bricks automatically separates from the casing andupper course and remains on the ingot since the wooden or fusible pins21 or other fastenings have been consumed or broken off during thestripping operation during the casting operation by reason`of theintense heat to which they were exposed and are thus no longer effectiveto support the lower course of bricks. The latter may now be readilyknocked ofi the ,ingot with a bar or-the like, an operation which isrelatively simple because of the fact that as this course of material'ismade of separate sections or f bricks it readily comes apart and alsobecause of the fact that the total volume or quantity of material in thecourse is relaf tively small.. In fact, under certain conditions it mayoftenI be deemed -unnecessary to remove the lower course of materialfrom the ingotV at all but instead to allow it to go with thev ingot tothe soaking pit as even if all of the material'should remain upon theingot by the time it reaches the it, the total quantity thereof isconsiderab y less than that remaining onthe ingot under presentpractice,` unless particularpains have been taken to remove it, and isthusordinarily notsuiiicient to cause undesirable accumula-v tion in thesoaking pit or otherwise I'interfere with the treatment of the ingottherein. r

for a second cast, such as, for instance, coating the inside of the topwith a suitable coating o f slurry77 or facing material which acts as acleavage plane when the top is stripped. As the upper course of bricksare free to expand and contract when required within the hot top casingthey are capable of use for a considerable number of times before theyare so disintegrated or worn as to require renewal, while of course thecasing itself is capable of use substantially indefinitely; thus as apractical matter it is onl necessary to renewthe lower course of bricksand fusible pins or other suitable fastenings after each cast and torenew the upper course of bricks at relatively considerable intervals.

While under ordinaryconditions the employment of the wooden blocks 24 asa means for supporting the hot top on the old is convenient, it will ofcourse beappare t that the blocks or the like might be made of somecompressible material of such character that it would allow the hot topto freely follow the ingot downward while it is shrinking, and undersuch circumstances the blocks could be left in place throughout the castinstead of being knocked away as when wooden yor other substantiallynon-compressible blocks are employed.

In Fig. 4 we have illustrated a slightly modified form of the inventionin which insteadI of employing a lower course of refrac- `tory materialwe utilize a curved metal shield 30 which extends around the inerperiphery of, the mold below the upper lining l5and is pinned 'in placeby fusible pins 21 in a manner similar to the bricks 20 heretoforedescribed. This metal shield or plate contacts adjacent portion of theupper course of bricky work, and that the'curved portion of the shieldis extended outwardly beyond the casing proper so as to span theclearance C between the hotftop' andthe I riold and thus form a sealbetween'the' parts at this lp ,int

which at least to some extent supplements or takes the'place of the sealformed b the congealed metal as heretofore describe In Fig. 5 we haveshown still another form of the invention in which the upper course ofbricks or other material in the hot top is faced on its inner .side withmetal. This metal is desirably in the form of a cast sleeve 32 having anoutwardly turned flange or shoulder 32 at its lower end upon which thebrick lining 40 can rest and which in turn rests on the ledge 16. Thebrick orother refractory lining 40 thus forms an insulator between themetal sleeve 32 and y the casing but does lnot normally entirely ill thespace between Ythese parts, the

` clearance 17 being left to permit lthe requisite .expansion of thebricks and having some further advantage as an insulating air space. Themetal Asleeve 32 thus comes in contact with the Huid metal in the topand after the ingot is poured the top is stripped' preferably in theform of a relatively thin v sheet 34 which extends around and againstthe inner face of the refractory and thus lies between the latter andthe molten metal in the top. In this form of the invention, the skirt ofthe casing below the ledge 16 which serves to support the refractory ispreferably curved downwardly and outwardly andthe metal lining 34similarly curved and extended beyond the casing sufficiently to span theclearance C as in the form of the invention shown in Fig. 4. Toinitially support the metal lining in the" hot top, the former, ifdesired, is provided at its upper end with a plurality of small tabs 34which, after the lining is inserted, are bent outwardly over theadjacent refractory material and thus serve to hold the metal lining inplace. When the hot top is stripped from the mold after the pouring ofthe ingot', the adherence of the liningto the metal in the hot top isgreater than the resistance oifered by these tabs so that the latterstraighten out and al- -5 low the casing and refractory to be strippedoff, the metal-lining 34' remaining on the 1ngot and passing therewithto the soaking pit; The use of this form of the invention, as well asthat shown in Fig. 4,'thus eliminates the transference pf.-anywrefractory material whatever to the soaking pit with the ingot andas the small amount of unconsumed metal remainingIl from the shieldorthe lining 34 as the .case may be is entirely unobjectionable duringthe treatment of the ingot in the soaking pit, these forms of theinvention will frequently vbe preferred over those employing the lowercourse of the brickwork. Of course a new metal lining must necessarilybe inserted each time the hot top is used but the'refractorymaterialonly requires renewal at relatively long 'inter-4 vals as it isquite thoroughly protected by the metal lining and kept out of contactwith the molten metal, in the hot top.

As the forms of the invention shown in Figs. 4, 5 and Gare used insubstantially the same manner as the form shown in the receding figuresas heretofore fully descri d, any extended reference thereto would besuperfluous as the samewill ,be readily comv prehended by those skilledin the art.

It will thus be apparent that we have provided an improved hot to whichmay be utilized for a plurality o successive casts by merely insertingafter each pouring a new lower course of bricks or other refractory` ora new shield or metal'linin'g Idepending on the particular form of theinvention and which embodies many otherl advantages and `novel featuresto which reference has heretofore been '.made. l

Moreover, while to enable those skilled in the art to readily understandand practice the invention, we have herein illustrated and describedseveral forms thereof with considerable particularity, we do not therebydesire or intend to specifically limit ourselves thereto or to anyprecise details in the design, construction and arrangement of thevarious parts of any of them as numerous modifications may be madetherein if desired to adapt the hot top to particular operatingconditions or for other purposes without de- .parting from the spiritand scope of the invention as defined in the appended claims. Havingthus described our invention we claim and desire to protect by LettersPatent of the United States 1. A hot top adapted to extend within theend of an ingot mold, and to rest upon the top of the ingot when poured,means for supporting the hot top temporarily during the pouringoperation, and parting means protecting the end of the hot top andfacilitating stripping of the hot top from the in 2. VIn a hot top ofthe full. floating type adapted to extend inside'the top of an in- ,gotmold comprising a casin means protecting the lower end -f the casing andadapted to secure parting between the casing and an ingot when the hottop is stripped therefrom.

3. In a hot top of the full floatingv type adapted to extend inside thetop of an ingot mold, comprising a casing, a heat retaining lining forthe casingincluding means protecting the lower en d of the casing andadapt` ed to secure parting between the casing and the ingot when thehot top is stripped theretoward the mold wall, said means being adaptedto Vfacilitate the stripping of the hot top from the ingot.

6. In a hot top for ingot molds, a casing, a lining therefor comprisingan upper course of semi-permanent material, means for supporting theupper course upon the casing, a

'lower course of material, and separate means for detachably supportingthe lower course from the casing.

7. In a hot top for ingot molds, a casing provided with an internalledge, a lining for the casing supported upon said ledge,` and a lowercourse of lining material detachably suspended from the bottom of saidcasing.

8. In a hot top for ingot molds, a casing, a lower lining course for theprotection of the lower end of said casing, said course comprisingelements previously formed with openings'l therethrough adapted toreceive .fastenings for removably attaching the course to said casing.

9. In a hot top-for ingot molds, a casing, a lower lining course for theprotection of the lower end of said casing, said course comprising aplurality .of non-plastic recertain of sai a lining therefor comprisingan upper course fractory' elements `with interftting edges, ementshaving openings therethrough a apted to receive fastenings ,forremovably attaching the course to said casing.

10. In a hot top for ingot molds, a casing,

of refractory' material, means for supporting the upper course upon thecasing, a lower lining course of refractory material meeting the uppercourse on the inner side of the hot topy and egrtending outwardlybeneath said casing, and separate means for detachably supporting thelower course from the casing.

11.-- In a hot top for ingot molds, a casing, a lining thereforcomprising an upper course of material, meansy for supporting the 'uppercourse upon the casing, a lower lining course' comprising a plurality ofseparate blocks,

and means for supporting-said last named I.course from the casing temorarily prior to and during the pouring o the metal, said last namedmeans being adapted to fail when the hot top is strippedI from the mold.

12. In a hot top for ingot molds, a casing, a lining thereforcomprisingfan uppercourse of material, means for supporting the uppercourse upon the casing, a lower lining course of refractory materialmeeting the upper course on the inner side of the hot top, said lowercourse comprising a plurality of separate blocks, and means forsupporting said last named course from the casing temporarily prior toand during the pouring of the metal, said last named means being adaptedY to fail when the hot top is stripped from the mold.

13. A device of the class described adapted for operative associationwith an ingot mold and comprising a casing, a semi-permanent,

lining of suitable material within the casing terminating short of thelower end thereof,

and releasably supported means below said' lining adapted to contactwith the surface of an ingot during the casting thereof in the mold andto separate from the casingv C and the lining when the latter are liftedfrom the mold after the ingot has been cast therein.

14. A hot top for an ingot mold comprising a casing adapted to extendinto the mouth of the mold, a suitable semi-permanent linving disposedwithin the casing and terminating-short of the bottom thereof, means forisupporting said lining in the casing and releasably supported means,extending below said lining and casing adapted to Contact with the upperend of the ingot as it is formed Withinthe mold and to separate from thelin-- ing and the casing when the latter are vstripped from the moldafter the ingot has been poured.

15. A hot top for aningot mold comprising a metal casing adapted toextend into the mouth of the mold and provided with ico means forsupporting the casing adjacentl thereto preparatory to the castingoperation, a lining of suitable material in the upper part of thecasing, means carried by the casing for Ysupporting said lining therein,means disv posed below said lining and enclosing the lower end of thecasing operative to rest on the surface of the ingot after the same hasbeen poured and means for securing said last mentioned means to thecasing adapted to fail and permit separation of said last mentionedmeans from the casing and the lining .when the latter are unitarilystripped from the mold after the completed. v

16. A hot top for an ingot mold comprispouring of the ingot has been inga metalliccasingfhaving its lower end formed to enter the mouth of themold,

meansA carried by the casing operative to support the casing adjacentthe mouth of the mold preparatory to the casting operation,

a liningof refractory material within the' casing and spaced from theinner face there-I 4 of, means for supporting the lining therein, meansextending below said lining and over isc 17. AA hot top for an ingotmold comprisf ing a casing having its lower end adapted to extend intothe mouth of the mold, a semipermanent lining of suitable material inthe upper part of the casing, means for supportl ing said lining thereinand a separate course ing a metallic-casing having its 'lower endada tedto extend. into the mouth of the of refractory material releasablysecured to the'casing below said lining and adapted to rest lon thesurfacev of the ingot after the same has been poured in the mold.

.18. A hot top .for an ingot mold compi-is- 'ing a casing having itsllower` end adapted to extend into the mouth of the mold, asemipermanent lining of suitable material in the upper part of thecasing, means for supporting the lining in the casing, a separate course'of refractory material disposed below said lining and means operativeto secure said course to the casing preparatory to the pour ing of theingot and to fail and permit the separation' of said course fromthecasing after the ingot has been poured to`thereby allow the casingand the lining to be stripped from the ingot as a unit.

19. A h ot top -for an ingot mold comprising a metallic casing havingits lower end adapted to extend into thel mouth of the mold, asemi-permanent liningof suitable material disposed in the upper part ofthe casing, means carried bythe casing for supporting the liningtherein, a lower course of refractory materlal disposed below saidlining and extending beyond the lower end of the casing and heatweakened means 'operative to initially secure said course 'to the casingpreparatory to the pouring of the ingot and to permit the separation ofsaid course from the casing after the ingot has been poured to therebyallow the casing and lining to be stri ped from the ingot as a unit. v20. A ot top for an ingot mold comprisduring the pouringv thereof topermit said course to separate from the caslngand the lining when thelatter are unitarily stripped from the4 ingot after the same has beenpoured.

21. A hot top comprising a casing, aV suitable lining disposed in theupper part of the casing, means disposed adjacent the bottom of thecasing adapted to contact with the .surface of the ingot after thelatter has been formed in the mold, and means for supporting the hot topin operative position on the mold during the pouring of the ingot and.operable to release said support and permit said first mentioned meansto support the hot top by engagement with said ingot during the coolingthereof after the ingot-has been poured, said first named means beingadapted to be stripped from the hot top in the removal of the latter. l

22. A hot top comprising a casing adapted to extendinto the mouth of themold, a lining for the upper. part of the casing, means 'for initiallysupporting the casing from the mold during the pouring of the ingot andmeans carried by the casing and extending over the lower end thereofadapted to engage the surface of the ingot after the same has beenpoured and support the hot top therefrom to thereby permit the hot topto sink relatively to the mold as the'ingot shrinks.v

while it is cooling, said last named means i being adapted to bestripped from' thev hot top inthe removal of the latter.

23. A hot top for ingot molds comprising a casing adapted to extend intothe mouth of the mold, a lining for the upper part of the casing,meansfor supporting the casing'in operative position on the moldpreparatory' if to and while the ingot is being poured, and meanscarried bythe casing and adapted to be stripped therefrom inthestripping operation' and extending under lthe lower extremity,thereof adapted to engage the ingot after it has been poured andthereafter sup.

port the hot top solely from the ingot y whereby the hot top is free tosink with the ingot relatively to the mold as the ingot shrinks duringcooling.

In witness whereof we have hereunto set our hands this-28th day ofDecember, 1928.

` WALTER M. CHARMAN. A

HARRY J. DARLINGTON.

mol a lining of suitable material disposed in the upper part of thecasing, means carned by the casing for sup orting the' lining fthereinfa lower course o vrefractory material disposed inthe casingbelow said lining weakened by4 heat extending between said lower courseand thecasing operative to secure them together. preparatory to the ofthe ingot and'to lose strength

